I just got back from a trip staying in the cabins and they were great! I loved having the option of making myself some french toast every morning and having the dishes cleaned for me when I got back after a day of parks. That said, the cabins resort is huge so if you're relying on Disney Transportation, it is one bus to the lobby and another to the park, adding up to 30 min every time you go to or from your cabin (you did mention the parking spot as an advantage so that may be moot).
That being said, I have stayed at CSR in the past and it is very pleasant. A little farther away from most things (not far from the All Star Resorts) but very comfortable (just don't rent the little boats, the marina is small so they have them geared down so they don't go very fast)
I've never stayed at FWL but I have toured the property and it is gorgeous.
I suppose your decision comes down to what matters most... Price, go with CSR. Convenience (kitchen) go with the cabins (proximity) go with FWL. Luxury definitely go with FWL.
Or if you plan on having any non park down days then I'd give the cabins another consideration. There is a lot to do there besides sleep. there is the campfire sing-along hosted by Chip and Dale followed by a movie, or the canals where you can rent canoes or bay lake where you can rent boats, or go on a fishing excursion, there is a petting zoo, horseback riding, and little pocket parks with playgrounds all around the property.
Hope this helps, although I feel like I may have given you too much to think about and maybe more questions than answers!